1660291 has 4 divisors (see below), whose sum is σ = 1663432. Its totient is φ = 1657152.

The previous prime is 1660289. The next prime is 1660297. The reversal of 1660291 is 1920661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1660291 - 2¹ = 1660289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1660297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561 + ... + 1906.

It is an arithmetic number, because the mean of its divisors is an integer number (415858).

2^1660291 is an apocalyptic number.

1660291 is a deficient number, since it is larger than the sum of its proper divisors (3141).

1660291 is an equidigital number, since it uses as much as digits as its factorization.

1660291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3140.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 1660291 is about 1288.5227976252. The cubic root of 1660291 is about 118.4117331856.

The spelling of 1660291 in words is "one million, six hundred sixty thousand, two hundred ninety-one".